Papermaking belt and process and apparatus for making same

ABSTRACT

The invention comprises a method for applying a curable resin to a reinforcing structure and an apparatus therefor. The apparatus comprises a working surface having a pattern of recesses therein structured and designed to at least partially receive a reinforcing structure, a means for disposing the reinforcing structure in the pattern of recesses of the working surface, a means for applying a fluid resinous material to the reinforcing structure disposed in the recesses of the working surface, and a means for solidifying the fluid resinous material to provide a patterned resinous framework joined to the reinforcing structure. The process comprises the steps of at least partially disposing the reinforcing structure in the recesses of a working surface, applying the fluid resinous material to the reinforcing structure, and then solidifying the fluid resinous material to form a patterned resinous framework joined to the reinforcing structure. Preferably, the reinforcing structure has voids, penetrable by the fluid resinous material, intermediate the first and second sides, and the resinous material occupies at least some of the voids in the reinforcing structure. The finished belt comprises a patterned resinous framework joined to the reinforcing structure such that a substantial portion of a bottom side of the resinous framework is between two opposite sides of the reinforcing structure.

FIELD OF THE INVENTION

The present invention relates to processes for making papermaking belts.More particularly, the present invention is concerned with a method ofmaking a belt comprising a reinforcing structure and a resinousframework joined thereto.

BACKGROUND OF THE INVENTION

Generally, through-air-drying papermaking processes include severalsteps. An aqueous dispersion of papermaking fibers is formed into anembryonic web on a foraminous member, such as Fourdrinier wire. Thisembryonic web is associated with a deflection member having amacroscopically-planar, and preferably non-randomly patterned networksurface which defines within the deflection member a plurality offluid-permeable deflection conduits. In a continuous papermakingprocess, this deflection member is in the form of an endless papermakingbelt. If the patterned network surface of the deflection member issubstantially continuous, the plurality of deflection conduits comprisesdiscrete conduits isolated from one another. If the patterned networksurface of the deflection member comprises a plurality of isolated fromone another protuberances, the plurality of conduits form asubstantially continuous area. The papermaking fibers are deflected intothe deflection conduits, and water is removed through the deflectionconduits, thereby an intermediate web is formed. The intermediate web isthen dried and, if desired, is foreshortened by creping.

The papermaking belt comprising the deflection member is described inseveral commonly-assigned U.S. Patents: U.S. Pat. No. 4,514,345, issuedApr. 30, 1985 to Johnson et al.; U.S. Pat. No. 4,528,239, issued Jul. 9,1985 to Trokhan; U.S. Pat. No. 5,098,522, issued Mar. 24, 1992; U.S.Pat. No. 5,260,171, issued Nov. 9, 1993 to Smurkoski et al.; U.S. Pat.No. 5,275,700, issued Jan. 4, 1994 to Trokhan; U.S. Pat. No. 5,328,565,issued Jul. 12, 1994 to Rasch et al.; U.S. Pat. No. 5,334,289, issuedAug. 2, 1994 to Trokhan et al.; U.S. Pat. No. 5,431,786, issued Jul. 11,1995 to Rasch et al.; U.S. Pat. No. 5,496,624, issued Mar. 5, 1996 toStelljes, Jr. et al.; U.S. Pat. No. 5,500,277, issued Mar. 19, 1996 toTrokhan et al.; U.S. Pat. No. 5,514,523, issued May 7, 1996 to Trokhanet al.; U.S. Pat. No. 5,554,467, issued Sep. 10, 1996, to Trokhan etal.; U.S. Pat. No. 5,566,724, issued Oct. 22, 1996 to Trokhan et al.;U.S. Pat. No. 5,624,790, issued Apr. 29, 1997 to Trokhan et al.; U.S.Pat. No. 5,628,876 issued May 13, 1997 to Ayers et al.; U.S. Pat. No.5,679,222 issued Oct. 21, 1997 to Rasch et al.; and U.S. Pat. No.5,714,041 issued Feb. 3, 1998 to Ayers et al., the disclosures of whichpatents are incorporated herein by reference.

Deflection of the papermaking fibers into the deflection conduits of thedeflection member can be induced by, for example, application ofdifferential fluid pressure to the embryonic web. One preferred methodof applying the differential pressure comprises exposing the embryonicweb to a vacuum through the deflection conduits of the deflectionmember. A sudden application of the differential fluid pressure to thefibers tends to separate some of the fibers deflected into thedeflection conduits from the web and from one another. In addition, as aresult of a sudden application of the pressure differential to the web,a certain number of partially dewatered fibers separated from theembryonic web could completely pass through the conduits of thedeflection member. These phenomena cause formation of so-called"pinholes" in the finished paper web, and also may lead to clogging ofthe vacuum dewatering machinery with the fibers separated from the web.

This undesirable creation of the pinholes may be mitigated by providinga leakage between the deflection member and the papermaking equipmentcreating the fluid pressure differential. One way of creating such aleakage comprises providing surface texture irregularities in thebackside network of the deflection member. Commonly-assigned U.S.Patents Nos.: U.S. Pat. No. 5,098,522 issued Mar. 24, 1992 to Smurkoskiet al.; and U.S. Pat. No. 5,364,504 issued Nov. 15, 1994 to Smurkoski etal. disclosed a process of making a backside textured belt, comprisingcasting a photosensitive resinous material over and through areinforcing structure while the reinforcing structure travels over atextured working surface. Commonly-assigned U.S. Pat. No. 5,275,700,issued Jan. 4, 1994 to Trokhan et al. disclosed a process of making abackside textured belt, comprising applying a coating of aphotosensitive resin to the reinforcing structure and pressing thereinforcing structure into a deformable surface so that the deformablesurface forms protrusions which exclude resin from certain areas,thereby creating a textured backside of the belt. Commonly-assigned U.S.Pat. No. 5,334,289 issued Aug. 2, 1994 to Trokhan et al. discloses aprocess for making a backside textured belt, comprising applying acoating of photosensitive resin to a reinforcing structure which hasopaque portions, and then exposing the resin to curing radiation throughthe reinforcing structure. The foregoing patents are incorporated hereinby reference.

Another way of mitigating the undesirable creation of the pinholes,developed by the present assignee, comprises making the belt havingdeflection conduits such that a substantial portion of each conduit isnot less than about 45 mils in each of the conduit's dimensions(measured in the general plane of the belt, i. e., an X-Y plane), asdisclosed in commonly-assigned U.S. Pat. No. 5,679,222 issued Oct. 21,1997 to Rasch et al., which is incorporated herein by reference.

Still, the search for improved products has continued.

The present invention provides a novel process for making an improvedpapermaking belt comprising a reinforcing structure and a resinousframework joined thereto. It is a benefit of the present invention toprovide a novel process for making a backside-textured papermaking belt.Another benefit of the present invention is that it provides a novelprocess for making a papermaking belt in which the depth of penetrationof the resin into the reinforcing structure is controllable such thatthe resin penetrates a predetermined portion of the thickness of thereinforcing structure, so as to provide acceptable bonding of the resinto the reinforcing structure, while maintaining the flexibility of thereinforcing structure, as well as the permeability to air and water.Still another benefit of the present invention is that it provides aprocess for reducing the amount of the resinous material required formaking the belt.

SUMMARY OF THE INVENTION

A papermaking belt that can be made by a process and an apparatus of thepresent invention comprises a reinforcing structure and a patternedresinous framework joined thereto. The reinforcing structure has a firstside and an opposite second side. The resinous framework has a top sideand a bottom side, the top and bottom sides corresponding to the firstand second sides of the reinforcing structure, respectively. Theresinous framework and the reinforcing structure are joined togethersuch that a substantial portion of the bottom side of the resinousframework is elevated over the second side of the reinforcing structure.That is, the belt has a distance formed between the second side of thereinforcing structure and the substantial portion of the bottom side ofthe resinous framework. During a papermaking process, this distanceprovides leakage between the belt and a dewatering papermakingequipment, thereby eliminating a sudden application of fluid pressuredifferential to a paper web disposed on the belt and mitigating aphenomenon known as "pinholling." The distance between the second sideof the reinforcing structure and the bottom side of the resinousframework may differentiate throughout the plane of the belt.

An apparatus for making the papermaking belt comprises a working surfacehaving a pattern of recesses therein, a means for disposing thereinforcing structure in the pattern of recesses of the working surface,a means for applying a fluid resinous material to the reinforcingstructure disposed in the recesses of the working surface, and a meansfor solidifying the fluid resinous material to provide a patternedresinous framework joined to the reinforcing structure. The pattern ofrecesses is structured and designed to at least partially receive thereinforcing structure therein. In a preferred continuous process, theapparatus further comprises a means for continuously moving thereinforcing structure in a machine direction.

A process for making the belt comprises the following steps. A fluidresinous material is provided. The fluid resinous material is preferablyselected from the group consisting of epoxies, silicones, urethanes,polystyrenes, polyolefins, polysulfides, nylons, butadienes,photopolymers, and any combination thereof. In one preferred embodimentthe fluid resinous material comprises a photosensitive resin. In anotherpreferred embodiment, the fluid resinous material comprises athermo-sensitive resin. Preferably, the fluid resinous material isprovided in a liquid state.

The next step comprises providing a reinforcing structure having a firstside, a second side opposite to the first side, and a thickness definedtherebetween. Preferably, a fluid-permeable reinforcing structure isused, such as, for example, a woven reinforcing structure. However, theuse of the reinforcing structure that is not fluid-permeable is alsocontemplated in the present invention. Preferably, the reinforcingstructure has voids intermediate its first and second sides, which voidsare penetrable by the fluid resinous material.

The next step comprises providing a working surface. The working surfacecomprises an external surface and a pattern of recesses therein. Therecesses have a depth and are structured and designed to receive thereinforcing structure therein.

The next step comprises at least partially disposing the reinforcingstructure in the recesses of the working surface. Various means, such assupport rolls and press rolls, may be used to facilitate disposing thereinforcing structure in the recesses. Because of the flexible nature ofthe reinforcing structure, the reinforcing structure can be onlypartially disposed in the recesses. In some embodiments, the reinforcingstructure is disposed in the pattern of recesses to extend beyond theexternal surface of the working surface. In these instances, it ispreferred that at least a portion of the voids penetrable by the fluidresinous material extends beyond the external surface of the workingsurface.

The next step comprises applying the fluid resinous material to thereinforcing structure. Preferably, the resinous material occupies atleast some of the voids in the reinforcing structure such as to "lockon," or "encase," portions of the reinforcing structure as toeffectively form a bond therebetween. Alternatively, the resinousmaterial may attach to the reinforcing structure, without locking onaround the portions thereof. In the latter case, the first side of thereinforcing structure preferably posses sufficient roughness or/and beadhesive, which can be achieved by special treatment of the reinforcingstructure.

The fluid resinous material may be applied to the reinforcing structurein the form of a substantially uniform layer,or--alternatively--according to a predetermined pattern. The formerembodiment is particularly relevant for the photosensitive curableresinous materials, while the latter embodiment--for the processes usinga patterned molding surface to deposit the resinous material onto thereinforcing structure. In the latter instance, the process furthercomprises the steps of providing a patterned molding surface juxtaposedwith the reinforcing structure, and depositing the fluid resinousmaterial into the molding pockets of the molding surface. The moldingsurface has a pattern of molding pockets therein, which pockets arestructured and designed to receive the fluid resinous material and thento deposit it onto the reinforcing structure. The plurality of moldingpockets may comprise a substantially continuous pattern, a pattern ofdiscrete pockets, or a semi-continuous pattern comprising a combinationof the substantially continuous pattern and the pattern of discretepockets. The molding surface may comprise a surface of a rotatablemolding roll, or a surface of an endless molding band.

The next step comprises solidifying the fluid resinous material to forma patterned resinous framework joined to the reinforcing structure. Thenature of the resinous material dictates a method of its solidifying.Preferably, the solidifying comprises a curing (i. e., a processinvolving cross-linking) of the resinous material. The photosensitiveresinous materials can be cured by a curing, typically UV, radiation.Some thermo-sensitive resinous materials can cure naturally, during acertain period of time. After the resinous material has solidified, itforms a resinous framework securely joined to the reinforcing structure,thus forming the papermaking belt.

DESCRIPTION OF THE DRAWINGS

While the Specification concludes with claims particularly pointing outand distinctly claiming the present invention, the invention will bebetter understood from the following description taken in conjunctionwith the associated drawings, in which like elements are designated bythe same reference numeral, and:

FIG. 1 is a schematic illustration of a process for making a paper webwith a papermaking belt made according to present invention.

FIG. 2 is a schematic and partial plan view of one exemplary embodimentof the papermaking belt made according to a process of the presentinvention, the belt including a reinforcing structure and a continuousresinous framework joined to the reinforcing structure.

FIG. 3 is a cross-sectional view taken along lines 3--3 of FIG. 2.

FIG. 4 is a schematic side elevational view illustrating one embodimentof the process and the apparatus according to the present invention formaking a papermaking belt comprising a curable photosensitive resinousmaterial.

FIG. 4A is a schematic cross-sectional view taken along lines 4A--4A ofFIG. 4.

FIG. 4B is a schematic cross-sectional view taken along lines 4B--4B ofFIG. 4A.

FIG. 4C is a schematic and more detailed cross-sectional view of anelement of the pattern of recesses of the working surface, shown in FIG.4B.

FIG. 5 is a schematic side elevational view illustrating anotherembodiment of the process and the apparatus according to the presentinvention for making a papermaking belt, the apparatus comprising amolding member.

DETAILED DESCRIPTION OF THE INVENTION

In the representative papermaking machine schematically illustrated inFIG. 1, the papermaking belt which could be made according to thepresent invention takes the form of an endless belt, a papermaking belt10. The papermaking belt 10 has a web-contacting side 11 and a backside12 opposite to the web-contacting side 11. The papermaking belt 10carries a paper web (or "fiber web") 27 through various stages of thepapermaking process. Processes of forming embryonic webs are describedin several references, such as, for example, U.S. Pat. No. 3,301,746,issued to Sanford and Sisson on Jan. 31, 1974; and U.S. Pat. No.3,994,771 issued to Morgan and Rich on Nov. 30, 1976, both patents areincorporated herein by reference.

The papermaking belt 10 travels in the direction indicated bydirectional arrow B around the return rows 19a and 19b, impression niproll 19k, return rolls 19c, 19d, 19e, and 19f, and anemulsion-distributing roll 19g. The loop around which the papermakingbelt 10 travels includes a means for applying a fluid pressuredifferential to the embryonic web 27, such as a vacuum pickup shoe 18aand a multi-slot vacuum box 18b. In FIG. 1, the papermaking belt 10 alsotravels around a predryer, such as flow-through dryer, 33 and passesthrough a nip formed between the impression nip roll 19k and a dryingdrum, such as Yankee drying drum, 28.

Although the preferred embodiment of the papermaking belt 10 is in theform of an endless belt shown in FIG. 1, the belt 10 can be incorporatedinto numerous other forms which include, for instance, stationary platesfor use in making hand sheets, or rotating drums for use with othertypes of continuous process. Regardless of the physical form which thepapermaking belt 10 can take, the belt 10 generally has certain physicalcharacteristics set forth below.

As best shown in FIGS. 2 and 3, the belt 10 is essentiallymacroscopically-monoplanar, and has the web-contacting side 11 and thebackside 12 opposite to the web-contacting side 11. The papermaking belt10 is said to be macroscopically-monoplanar because when a portion ofthe belt 10 is placed into a planar configuration, the web-contactingside 11, viewed as a whole, is essentially in one plane. It is said tobe "essentially" macroscopically monoplanar to recognize the fact thatdeviations from absolute planarity are tolerable, while not preferred,so long as the deviations are not substantial enough to adversely affectthe performance of the belt 10 for the purposes of a particularpapermaking process.

The papermaking belt 10 which can be made in accordance with the presentinvention generally comprises two primarily elements: a framework 50a(preferably, a hardened polymeric resinous framework made of a flowableresinous material 50) and a reinforcing structure 40. The reinforcingstructure 40 has a first side 41 and a second side 42 opposite to thefirst side 41. The first side 41 may contact papermaking fibers duringthe papermaking process, while the second side 42 typically contacts thepapermaking equipment, such as, for example, a vacuum pickup shoe 18aand a multi-slot vacuum box 18b (both shown in FIG. 1).

The reinforcing structure 40 can take any number of different forms. Itcan comprise a woven element, a non-woven element, a screen, a net, aband, a plate, etc. The preferred reinforcing structure 40 isair-permeable, but it should be understood that air-impermeablereinforcing structure 40 is also contemplated in the present invention.In one preferred embodiment, the reinforcing structure 40 comprises awoven element formed by a plurality of machine-directional yarnsinterwoven with a plurality of cross-machine directional yarns, as shownin FIGS. 2 and 3. More particularly, the woven reinforcing structure 40may comprise a foraminous woven element, such as disclosed incommonly-assigned U.S. Pat. No. 5,334,289, issued in the name of Trokhanet al., on Aug. 2, 1994, and incorporated by reference herein. Thereinforcing structure 40 comprising a woven element may be formed by oneor several layers of the interwoven yarns, the layers beingsubstantially parallel to each other and interconnected in a contactingface-to-face relationship. Commonly-assigned U.S. Pat. No. 5,679,222,issued to Rasch et al. on Oct. 21, 1997 is incorporated by referenceherein. Commonly assigned U.S. Pat. No. 5,496,624, issued on Mar. 5,1996 to Stelljes, Jr. et al., is incorporated herein by reference toshow a suitable reinforcing structure 40.

The reinforcing structure 40 of the belt 10 strengthens the resinousframework 50a and preferably has a suitable projected area onto whichthe papermaking fibers can deflect under pressure. According to thepreferred embodiment of the present invention, the reinforcing structure40 is fluid-permeable. As used herein, the term "fluid permeable" refersto a condition of the reinforcing structure 40, which condition allowsfluids, such as water and air, pass through the reinforcing structure 40in at least one direction. As one skilled in the art will readilyrecognize, the belts comprising a fluid-permeable reinforcing structuresare typically used in through-air-drying processes of making a paperweb.

As shown in FIGS. 2 and 3, the reinforcing structure 40 is joined to theresinous framework 50a. The resinous framework 50a comprises asolidified, and preferably cured, resinous material 50, i. e., theresinous framework 50 is a solid phase of the fluid resinous material50a. In that sense, the terms "resinous material 50" and "resinousframework 50a" may be used interchangeably where appropriate in thecontext of the present Application. The resinous framework 50a has a topside 51 and a bottom side 52 opposite to the top side 51. One skilled inthe art will appreciate that the terms "top" and "bottom" areconventionally used herein for the definition purposes, and in thepresent context are descriptive only insofar as the belt 10 isillustrated in FIG. 3. During the papermaking process, the top side 51of the framework 50a contacts the papermaking fibers, thereby definingthe pattern of the paper web being produced. In the finished belt 10,the web-contacting side 11 comprises the top side 51 of the resinousframework 50a. In some embodiments, portions of the bottom side 52 ofthe framework and the second side 42 of the reinforcing structure may bedisposed in the same plane. In these instances, the portions of thebottom side 52 of the framework 50a may contact the papermakingequipment. According to the present invention, a substantial portion ofthe bottom side 52 of the framework 50a does not contact the papermakingequipment. Instead, the substantial portion of the bottom side 52 iselevated over the surface of the papermaking equipment such that adistance Z is formed therebetween, as will be explained in greaterdetail below. The substantial portion of the bottom side 52 is betweenthe first and second sides 41, 42 of the reinforcing structure 40. Theterm "substantial portion" refers to a portion of the bottom side 52,which portion is not disposed in the same plane in which the second side42 of the reinforcing structure 40 is disposed, and a relative size ofwhich portion is defined as a projected area of that portion on thegeneral plane of the belt 10. That is, the substantial portion of thebottom side 52 of the resinous framework 50a is elevated (as shown inFIG. 3) over the second side 42 of the reinforcing structure 40, and thedistance Z (which may vary) is formed therebetween. Thus, during thepapermaking process, the substantial portion of the bottom side of theresinous framework 50a does not contact the surface of the papermakingdewatering equipment. The substantial portion of the bottom side 52(viewed as an area projected to the general plane of the belt 10) ispreferably at least about 45%, more preferably at least about 65%, andmost preferably at least about 85%, relative to the entire projectedarea of the bottom side 52. It should be understood that projected areasformed by the yarns of the reinforcing structure 40 are not counted.

It should be understood that the distance Z may differentiate (notshown) between different parts of the finished belt 10. A desirable sizeof the substantial portion of the bottom side 52 is defined by therelative geometry of the belt 10 and the dewatering equipment, theextent of the distance Z, and other parameters of a particularpapermaking process. For a particular belt 10, the substantial portionof the bottom side 52 should be sufficient to provide the leakagebetween surface of the papermaking equipment creating fluid pressuredifferential and the backside 12 of the papermaking belt 10.

The desired size of the substantial portion is preferably defined by adesired leakage between the belt 10 and the papermaking equipmentproviding the fluid pressure differential during the papermakingprocess. The leakage of at least about 35 Marlatts at pressuredifferential of 7 inches of Mercury is prefered. A conversion fromMarlatts into standard cubic centimeters/minute can be made by insertingthe reading measured in Marlatts into the following equation where x isthe reading in Marlatts and y is the corresponding value in standardcc/minute:

    y=36.085+52.583x-0.07685x.sup.2.

This equation for converting Marlatts into standard cc/min was developedby calibrating the flow meter to standard cc/min. using a Buck OpticalSoap Bubble Meter. The commonly assigned and incorporated herein U.S.Pat. No. 5,334,289 describes in greater detail the test methods and adevice utilized to conduct measurements of the leakage (U.S. Pat. No.5,334,289, at 65:8-68:7). The device described in U.S. Pat. No.5,334,289 may be utilized to measure the backside texture leakage of thepapermaking belt 10 made in accordance with the present invention.

The deflection conduits 60 (FIGS. 2 and 3) extend between the top side51 and the bottom side 52 of the resinous framework 50. In one preferredembodiment, shown in FIGS. 2 and 3, the plurality of discrete deflectionconduits is distributed in a pre-selected non-random pattern throughoutthe substantially continuous resinous framework 50a. The patterns of theconduits' distribution, as well as the conduits' shapes, may vary, asone skilled in the art will understand.

Another embodiment (not shown) of the belt 10 comprises a substantiallycontinuous (as opposed to discrete) conduit 60 encompassing a pluralityof discrete portions of the resinous framework 50a. In the latterinstance, preferably the plurality of the discrete portions of theresinous framework 50a comprises a plurality of protuberances extendingoutwardly from the first side 41 of the reinforcing structure 40 anddistributed throughout the substantially continuous conduit 60 in apre-selected non-random pattern. As used herein, a pattern is said to be"substantially" continuous to indicate that minor deviations fromabsolute continuity may be tolerated, as long as these deviations do notadversely affect the performance and desired qualities of the finalproduct--the papermaking belt 10. The papermaking belt 10 whichcomprises a combination of the two foregoing embodiments (i. e.,comprising the plurality of discrete conduits and the substantiallycontinuous conduit) is also contemplated in the present invention.Commonly assigned U.S. Pat. No. 5,245,025 issued on Sep. 14, 1993, inthe names of Trokhan et al., is incorporated herein by reference.

The framework 50a may comprise the bottom side 52 having a network ofpassageways that provide backside surface texture irregularities, asdescribed in commonly-assigned U.S. Pat. No. 5,275,700 issued on Jan. 4,1994 to Trokhan, which patent is incorporated by reference herein. Thetwo embodiments of the framework 50a--one having the distance Z betweenthe backside 52 of the framework 50a, and the other having the backsidetexture irregularities--beneficially provide leakage between the belt 10a surface of the papermaking equipment creating the fluid pressuredifferential. The leakage reduces, and can even eliminate altogether, asuddenness of the application of the vacuum pressure to the paper web,thereby mitigating a phenomenon known as pinholing.

The framework 50a which is "angled" relative to the first surface 41 ofthe reinforcing structure 40 is contemplated in the present invention.As used herein the term "angled" in conjunction with "framework 50a"refers to a framework 50a in which--if viewed in a cross-section--acuteangles are formed between the first surface 41 of the reinforcingstructure 40 and longitudinal axes of either discrete deflectionconduits--in the instance of the continuous framework 50a, or discreteprotuberances--in the instance of the framework 50a comprising aplurality of discrete protuberances. These embodiments are disclosed incommonly assigned patent applications Ser. No. 08/858,661; and Ser. No.08/858,662, both applications entitled "Cellulosic Web, Method andApparatus For Making the Same Using Papermaking Belt Having AngledCross-sectional Structure, and Method Of Making the Belt," and filed inthe name of Larry L. Huston on May 19, 1997, the disclosures of whichapplications are incorporated herein by reference.

A first step of the process for making a papermaking belt 10 accordingto the present invention comprises providing a flowable resinousmaterial 50. As used herein, the "flowable resinous material" refers toa wide variety of polymeric resins and the like materials that canachieve and maintain under certain conditions a fluid state sufficientto be deposited onto the reinforcing structure 40 having voids thereinand to at least partially penetrate these voids such as the reinforcingstructure 40 and the resinous material could be joined together. Theflowable resinous material 50 is capable of solidifying under certainconditions, and preferably, the flowable resinous material 50 is capableof being cured. The term "curing" refers to solidification of the fluidresinous material 50a, during which solidification cross-linking occurs.The flowable resinous material 50 of the present invention may comprisea material selected from the group consisting of: epoxies, silicones,urethanes, polystyrenes, polyolefins, polysulfides, nylons, butadienes,photopolymers, and any combination thereof.

The examples of the suitable liquid resinous material 50 comprisingsilicones, include, but are not limited to: "Smooth-Sil 900,""Smooth-Sil 905," "Smooth-Sil 910," and "Smooth-Sil 950." The examplesof the suitable liquid resinous material 50 comprising polyurethanes,include, but are not limited to: "CP-103 Supersoft," "Formula 54-290Soft," "PMC-121/20," "PL-25," "PMC-121/30," "BRUSH-ON 35," "PMC-121/40,""PL-40," "PMC-724," "PMC-744," "PMC-121/50," "BRUSH-ON 50," "64-2 ClearFlex," "PMC-726," "PMC-746," "A60," "PMC-770," "PMC-780," "PMC-790." Allthe above exemplary materials are commercially available from Smooth-On,Inc., 2000 St. John Street, Easton, Pa., 18042. Other examples of theliquid resinous material 50 include multi-component materials, such as,for example, a two-component liquid plastic "Smooth-Cast 300," and aliquid rubber compound "Clear Flex 50," both commercially available fromSmooth-On, Inc.

Photosensitive resins may also be used as the resinous material 50. Oneexemplary embodiment of the process using the photosensitive resin asthe resinous material 50 is shown in FIG. 4. The photosensitive resinsare usually polymers that cure, or cross-link, under the influence ofradiation, typically ultraviolet (UV) light. References containing moreinformation on liquid photosensitive resins include Green et al.,"Photocross-Linkage Resin Systems," J. Macro-Sci. Revs Macro Chem. C21(2), 187-273 (1981-82); Bayer, "A Review of Ultraviolet CuringTechnology", Tappi Paper Synthetics Conf. Proc., Sep. 25-27, 1978, pp.167-172; and Schmidle, "Ultraviolet Curable Flexible Coatings", J. ofCoated Fabrics, 8, 10-20 (July, 1978). All the preceding threereferences are incorporated herein by reference. Especially preferredliquid photosensitive resins are included in the Merigraph series ofresins made by Hercules Incorporated, Wilmington, Del. A most preferredresin is Merigraph resin EPD 1616.

The examples of thermo-sensitive resins that can comprise the resinousmaterial 50 of the present invention include, but are not limited to: agroup of thermoplastic elastomers Hytrel® (such as Hytrel® 4056,Hytrel®7246, and Hytrel®8238); and Nylon Zytel® (such as Zytel®101L, andZytel®132F), commercially available from DuPont Corporation ofWilmington, Del.

Preferably, the flowable resinous material 50 is provided in a liquidform. The present invention, however, contemplates the use of theflowable resinous material 50 which is provided in a solid form. In thelatter instance, an additional step of fluidizing the resinous material50 is required. The flowable resinous material 50 is preferably suppliedto a source 55 which provides for the proper conditions (such as, forexample, temperature) to keep the resinous material 50 in a fluid state.As used herein, the term "fluid" refers to a condition, state, or phase,of the resinous material 50, in which condition the resinous material 50is capable of flowing and which allows the resinous material 50 bedeposited onto a three-dimensionally-patterned surface such that theresinous material 50 substantially conforms to a three-dimensionalpattern of the patterned surface. If thermoplastic or thermosettingresins are used as the resinous material 50, typically, a temperatureslightly above the melting point of the material is desired to maintainthe resin in a fluid state. The material is considered to be at or abovethe "melting point" if the material is wholly in the fluid state. Asuitable source 55 is a trough schematically shown in several drawingsof the present application. The trough may have a closed end bottom andclosed side walls and outboard side wall. The inboard side wall of thetrough may be open allowing the flowable resinous material 50 disposedtherein to freely contact and communicate with a molding member 70 (FIG.5), as described herein below. If the resinous material comprises athermoplastic resin, the source 55 and the molding member 70 ispreferably heated to prevent premature solidification of the liquidresinous material 50.

In the embodiment of the process of the present invention, shown in FIG.5, a suitable source 55 is a trough. The trough may have a closed endbottom and closed side walls and outboard side wall. The inboard sidewall of the trough may be open allowing the flowable resinous material50 disposed therein to freely contact and communicate with a moldingmember 70, as described herein below. In the embodiment of the processshown in FIG. 4, a coating of the flowable resinous material 50 isapplied to the reinforcing structure 40 by the source comprising anozzle.

The second step of the process according to the present inventioncomprises providing a reinforcing structure 40. As has been explainedabove, the reinforcing structure 40 is a substrate that may comprise avariety of different forms, such as, for example, a woven fabric, ascreen, a band, etc. A more detailed description of the reinforcingstructure 40, particularly one comprising a woven element, may be foundin commonly-assigned U.S. Pat. No. 5,275,700 incorporated herein byreference. In the formed papermaking belt 10, the first side 41 faces(and in some embodiment may contact) the papermaking fibers during thepapermaking process, while the second side 42, opposite to the firstside 41, faces (and typically contacts) the papermaking equipment. Asused herein, the first side 41 and the second side 42 of the reinforcingstructure 40 are consistently referred to by these respective namesregardless of incorporation (i. e., prior, during, and after theincorporation) of the reinforcing structure 40 into the papermaking belt10.

A distance between the first side 41 and the second side 42 of thereinforcing structure 40 defines its thickness and is designated hereinas "h" (FIG. 3). According to the present invention, the preferredreinforcing structure 40 has voids 49 intermediate the first side 41 andthe second side 42, as shown in FIG. 3. In the reinforcing structure 40comprising a woven element (as shown in FIG. 3), the voids 49 may be anatural occurrence of a weave pattern. The voids 49 are such that thefluid resinous material 50 is capable of penetrating the voids 49 sothat the resinous material 50 and the reinforcing structure 50 aresecurely joined together after the resinous material 50 has solidifiedand transformed into the resinous framework 50a. That is, thecombination of viscosity of the fluid resinous material 50 anddimensions and shapes of the voids 49 preferably allows the fluidresinous material 50 to penetrate the voids 49 and to "lock on" aroundat least some portions of the reinforcing structure 40 such as toeffectively form a "bond" with the reinforcing structure 40.

While the reinforcing structure 40 having voids 49 therein is preferred,the present invention contemplates the use of the reinforcing structurehaving no such voids, or having the voids which are not penetrable bythe liquid resinous material 50. In this instance, the reinforcingstructure 40, especially its first side 41, is such that the resinousmaterial 50 can attach thereto to sufficiently join the reinforcingstructure 40. For this purpose, the reinforcing structure 40, especiallyits first side 41, preferably has a sufficient roughness, eitherinherently, or as a result of a special treatment. Alternatively oradditionally, the first side 41 of the reinforcing structure can betreated with a suitable adhesive to cause the attachment of the resinousmaterial 50 to the reinforcing structure 40.

In the preferred continuous process of the present invention, thereinforcing structure 40 continuously moves in a machine direction,indicated in several figures as "MD." The use of the term "machinedirection" herein is consistent with the traditional use of the term inpapermaking, where this term refers to a direction which is parallel tothe flow of the paper web through the papermaking equipment. As usedherein, the "machine direction" is a direction parallel to the flow ofthe reinforcing structure 40 during the process of the presentinvention. Any means known in the art and suitable for a given processmay be used to provide the continuous movement of the reinforcingstructure 40. Because some types of the resinous material 50 require arelatively longer time to solidify compared to a "pot time," i. e., thetime during which the resinous material 50 can be maintained in a liquidstate, the movement of the reinforcing structure 40 may be indexed, ifdesired, such that the belt 10 is constructed portion-by-portion, as oneskilled in the art will readily recognize.

The next step comprises providing a working surface 21. As used herein,the term "working surface" refers to a surface of a working member 20,structured and designed to provide support for the reinforcing structure40 when the reinforcing structure 40 receives the flowable resinousmaterial 50 thereon. The working member 20 may comprise variousstructures. FIG. 4 shows the working member 20 in the form of arotatable roll 20a rotating in a direction indicated by a directionalarrow "A," while in FIG. 5 the working member 20 comprises an endlessband 20b traveling in the machine direction MD.

Regardless of a specific embodiment of the working member 20, theworking surface 21 posses certain characteristics, in accordance withthe present invention. Most importantly, FIGS. 4A and 4B show that theworking surface 21 has a pattern of recesses 24 therein capable toreceive the reinforcing structure 40 therein. The pattern of recesses 49is structured and designed such that the reinforcing structure 40 can beat least partially recessed in the recesses 24, as best shown in FIG.4B. The recesses 49 may be formed by any means known in the art, suchas, for example, engraving, molding, extrusion, etc. As used herein, the"working surface" 21 is a generic term referring to all exposed surfacesin contact with the reinforcing structure 40, including an external (orthe most elevated) surface 22 and a surface(s) of the recesses 24. Therecesses 24 are conventionally said to have a "bottom" 25 and "walls"26, as schematically shown in FIG. 4C. In FIG. 4A, the working surface21a comprises an external surface 22a (or a surface corresponding to agreater diameter of the roll 20a) and inner surfaces 23a of the recesses24. In FIG. 5, the working surface 21b comprises an external surface 22band inner surfaces 23b of the recesses 24 in the band 20b. It is saidthat the reinforcing structure 40 is "at least partially" recessed inthe pattern of recesses 24 to recognize that because of the flexibilityof the reinforcing structure 40, in some embodiments, portions of thereinforcing structure 40 may not be completely recessed within therecesses 24, which may be tolerable as long as it does not adverselyaffect the process and the final product of the present invention.

According to the present invention, the recesses 24 have at least onedepth "D" (FIGS. 4B and 4C) which is preferably less than the thicknessh of the reinforcing structure 40. The difference between the thicknessh of the reinforcing structure 40 and the depth D of the recesses 24ensures that the reinforcing structure 40 extends beyond (or "above"with reference to FIG. 4B) the working surface 21. Preferably, thereinforcing structure extends beyond the external surface 22 of theworking surface 21 such that at least a portion of the voids 49penetrable by the fluid resinous material 50 also extend beyond theexternal surface 22 of the working surface 20, as best shown in FIG. 4B.For illustration only, in FIG. 4B, a symbol "V" schematically designatesa "vertical" dimension of one type of the voids 49 between one of theyarns of the woven reinforcing structure 40 and the external surface 22aof the working surface 21a. That is, if the reinforcing structure 40comprises a woven element, preferably a clearance exists between atleast the uppermost yarn of the reinforcing structure 40 and theexternal surface 22 of the working surface 21, as best shown in FIGS. 4Aand 4B. If desired, the recesses 49 may have differential depths.

It should be understood that while the embodiment in which the depth Dof the recesses 49 is less than the thickness h of the reinforcingstructure 40 is preferred, it is not necessary. In the present inventionembodiments are contemplated, in which the depth D of the recesses 49 isequal to or even greater than the thickness h of the reinforcingstructure 40, as will be explained below in greater detail.

The next step in the process of the present invention comprisesdepositing the reinforcing structure 40 in the recesses 49 of theworking surface 20. Any means known in the art may be used for thisstep. In FIG. 5, a press roll 27 and a plurality of support rolls 27afacilitate registering of the reinforcing structure 40 within therecesses 24 of the working surface 21a. The process of the presentinvention may be indexed such as to allow one to register a portion ofthe reinforcing structure 40 which contacts the working surface 20, thenmove the working surface 21 having the portion of the reinforcingstructure 40 recessed therein to the next location, where the fluidresinous material 50 is applied to the reinforcing structure 40, andthen the process is repeated. This embodiment is not specificallyillustrated but can be easily visualized by one skilled in the art basedon the several drawings of the present Application.

The next step comprises applying the fluid resinous material 50 to thereinforcing structure 40. Depending on a specific embodiment of theprocess of the present invention, the fluid resinous material 50 may beapplied using a variety of means. In the embodiment of FIG. 4, the fluidresinous material 50 is applied to the reinforcing structure 40 by thenozzle 55 forming a layer of the fluid resinous material 50. In thisinstance, it is highly preferred that the resinous material 50 be evenlyapplied across the width of the reinforcing structure 40, therebyforming a substantially uniform layer of the resinous materialcontacting the reinforcing structure 40. In FIG. 4, the reinforcingstructure 40 travels in the machine direction MD up, over, and about therotatable roll 20a, and return rolls 29a, 29b, and 29c. Thickness of theresinous material 50 applied to the reinforcing structure 40 may becontrolled to a pre-selected value, depending on an expected use of thebelt 10 being constructed. Any suitable means for controlling thethickness can be used. For example, in FIG. 4, a roll 28a is juxtaposedwith the working member 20 comprising the roll 20a to form a niptherebetween. A clearance between the roll 28a and the working surface21a of the roll 20a can be controlled mechanically by means not shown.

If the resinous material 50 is selected from photosensitive resins, amask 15 can be used in juxtaposition with the layer of the resinousmaterial 50, to shield certain areas of the liquid photosensitive resinfrom exposure to curing radiation, as described in commonly assignedU.S. Pat. Nos. 4,514,345; and 5,275,700, incorporated herein byreference and referred to above. In FIG. 4, the mask, preferablycomprising an endless loop, travels in the direction indicated bydirectional arrows D1 about rolls 28a and 28b. In the embodiment shownin FIG. 4, the control of the thickness of the resinous material 50applied to the reinforcing structure 40 and the juxtaposition of themask 15 relative to the resinous material 50 occur simultaneously.

FIG. 5 shows the embodiment of the process of the present invention, inwhich the fluid resinous material 50 is applied to the reinforcingstructure 40 by a molding member 70. As used herein, the "moldingmember" 70 is a patterned structure designed to first, receive the fluidresinous material 50 thereby forming a predetermined pattern of theresinous material 50 therein, and then transfer the resinous material 50onto the reinforcing structure in a predetermined pattern. In thepreferred continuous process, the molding member 70 may comprise avariety of different embodiments. In the embodiment shown in FIG. 5, themolding member 70 comprises an endless band, a portion of which travelsin juxtaposition with the reinforcing structure 40 and the workingsurface 20. One skilled in the art will understand, however, that themolding member 70 may comprise a rotatable roll (not shown). Regardlessof its embodiment, the molding member 70 comprises a molding surface 71having a three-dimensional pattern thereon. The molding surface 71 is asurface onto/into which the fluid resinous material 50 is deposited. Themolding surface 71 is structured and designed to receive the flowableresinous material 50 such that the flowable resinous material 50substantially conforms to the three-dimensional pattern of the moldingsurface 71. Preferably the molding surface 71 comprises a pre-selectedpattern of molding pockets 72 therein. In a preferred continuous processof the present invention, the molding member 70 continuously moves at atransport velocity thereby carrying the resinous material 50 therein.One skilled in the art will readily appreciate that in the embodimentscomprising the rotatable molding roll or rolls, the transport velocitycomprises a surface velocity measured at the circumferences of themolding surface. In the embodiment of FIG. 5, comprising the moldingmember 70 in the form of the endless band, the transport velocity is avelocity of the band.

As used herein, the "molding pockets" 72 refers to a pattern ofdepressions, or cavities, in the molding surface 71, which are designedto receive therein the fluid resinous material 50 from a source 55, andthen to transfer the fluid resinous material 50 to the reinforcingstructure 40 such as to deposit the fluid resinous material 50 onto thereinforcing structure 40 in a pre-determined pattern. The moldingpockets 72 may comprise a substantially continuous pattern in themolding surface 71; in this instance, the resinous material 50 istransferred onto the reinforcing structure 40 in a substantiallycontinuous pattern to form a substantially continuous resinous framework50a, as described above. Alternatively, the molding pockets 72 maycomprise a pattern of discrete depressions, or cavities. In the latterinstance, the resinous material 50 is transferred from the moldingpockets 72 to the reinforcing structure 40 in a pattern comprising aplurality of discrete protuberances, as described above. A pattern (notshown) comprising a combination of the substantially continuous moldingpockets and the discrete molding pockets (i. e., a so-called"semi-continuous" pattern) is also contemplated by the presentinvention.

The framework 50a which is "angled" relative to the first surface 41 ofthe reinforcing structure 40 is contemplated in the present invention.As used herein the term "angled" framework 50a refers to a framework 50ain which--if viewed in a cross-section--acute angles are formed betweenthe first surface 41 of the reinforcing structure 40 and longitudinalaxes of either discrete deflection conduits--in the instance of thecontinuous framework 50a, or discrete protuberances--in the instance ofthe framework 50a comprising a plurality of discrete protuberances.These embodiments are disclosed in commonly assigned patent applicationsSer. No. 08/858,661, and Ser. No. 08/858,662, both applications entitled"Cellulosic Web, Method and Apparatus For Making the Same UsingPapermaking Belt Having Angled Cross-sectional Structure, and Method OfMaking the Belt," and filed in the name of Larry L. Huston on May 19,1997, the disclosures of which applications are incorporated herein byreference.

The molding pockets 72 have at least one depth. In the embodiment shownin FIG. 5, the depth of the molding pockets 72 generally defines athickness of the resinous material 50 deposited from the molding pockets72 onto the reinforcing structure 40. As used herein, the term "depth"of the molding pocket(s) 72 indicates an extent of thegeometrically-distinct depression(s) into the molding member 70.Virtually an unlimited number of shapes and their permutations of themolding pockets 72 having differential depths may be used in the presentinvention. "Angled" configurations of the molding pockets 72 may be usedto produce the "angled" pattern of the resinous framework 50a, asexplained herein above. The embodiment of the process of the processinvention illustrated in the FIG. 5 allows one advantageously to createalmost any desired shape of the resinous framework 90 by providing thecorrespondingly-shaped molding surface 71.

The pattern of the molding pockets 72 may be made by any method known inthe art, including, but not limited to, engraving, and molding/casting.The molding surface 71 may be constructed by using an existingpapermaking belt 10 having a desirable pattern of the resinous framework50a. In this instance, the belt 10 is used as a template, onto which asuitable mold material may be applied to form, after its solidification,a molding surface 71. That, this molding surface 71 can be attached tothe molding member 70 by any suitable means known in the art. Of course,where applicable, the entire molding member may be constructed asdescribed herein above. One example of mold materials that may be usedis, but is not limited to: "Brush-On 50," commercially available fromSmooth-On, Inc.

In FIG. 5, the flowable resinous material 50 is deposited into themolding pockets 72 of the molding surface 71 by, generally, firstcontacting the molding surface 71 with the flowable resinous material50, and then removing excess of the resinous material 50 from themolding surface 71 as the molding surface 71 is moving. Preferably, theexcess of the flowable resinous material 50 is removed into the source(trough in FIG. 5) 55, thereby reducing, or even eliminating, waste ofthe resinous material 50. Any suitable depositing means known in the artmay be used in the apparatus 10 of the present invention to perform thisstep. Removing of the excess of the resinous material 50 from themolding surface 71 may be accomplished by wiping and/or scraping theexcess material from the molding surface 71.

In FIG. 5, the step of applying the fluid resinous material 50 to thereinforcing structure 40 comprises continuously transporting thereinforcing structure 40 at the transport velocity such that a portionof the reinforcing structure 40 is in a face-to-face relationship with aportion of the molding surface 71, and transferring the flowableresinous material 50 from the molding pockets 72 of the molding surface71 onto the reinforcing structure 40 in the pre-selected pattern. Ifdesired, the molding pockets 72 can be treated with a release agent 60prior to the step of depositing the resinous material 50 into themolding pockets 72, to facilitate the transferal of the resinousmaterial 50 from the molding pockets 72 onto the reinforcing structure40.

In FIG. 5, the working member 20, comprising the band 20b, travels inthe machine direction MD about support rolls 29a and 29b rotating in thedirection indicated by the directional arrow "A." The reinforcingstructure 40 comes into contact with the working surface 71 and getsrecessed within the working surface 21 at a nip formed between thesupport roll 29a and a press roll 27. In FIG. 5, the reinforcingstructure 40 is also supported by rolls 27a. The molding member 70travels around support rolls 79a, 79b, 29b, 79c, 79d, and 79f. Thereinforcing structure 40 comes into a face-to-face relationship with themolding surface at a nip formed between the support roll 79b and theband 20b. Starting at this point, the corresponding portions of thereinforcing structure 40 recessed within the working surface 21 and themolding surface 71 travel in a face-to-face, preferably contacting,relationship during a pre-determined period of time sufficient to causethe resinous material 50 to be transferred from the molding pockets 72of the molding surface 71 onto the reinforcing structure 40 and at leastpartially solidify such as to retain the shape after the molding surface71 has disassociated from the reinforcing structure. In the embodimentof FIG. 5, the transferal of the resinous material 50 from the moldingsurface 71 to the reinforcing structure 40 is advantageously facilitatedby gravitation, for at some point, the molding surface 71 is above thereinforcing structure 40. It should be understood that the resinousmaterial 50 can partially solidify while associated with the moldingsurface 71 and before the resinous material 50 gets transferred from themolding surface 71 to the reinforcing structure 40. In some embodiments,a change of the viscosity of the resinous material 50 is contemplated,prior to its deposition onto the reinforcing structure 40. However, ashas been pointed out above, the resinous material 50 should retainviscosity sufficient to allow the resinous material 50 and thereinforcing structure 40 join together.

Preferably, the portion of the reinforcing structure 40 facing themolding surface 71 contacts the molding surface 71 for a predeterminedperiod of time. The process using the molding surface 71, principallyillustrated in FIG. 5, is described in greater detail incommonly-assigned and co-pending application titled "Papermaking Beltand Process for Making the Same," filed in the name of Ampulski on thesame date as the present Application has been filed, which Applicationis incorporated herein by reference.

Regardless of a specific method of applying the resinous material 50 tothe reinforcing structure 40, in the preferred embodiment the fluidresinous material 50 has the viscosity allowing the fluid resinousmaterial 50 to penetrate at least a portion of the voids 49 of thereinforcing structure 40. According to the present invention, a portionof the fluid resinous material 50 must work its way beyond the firstside 41 of the reinforcing structure 40 to reach the voids 49 such as toat least partially encase, or "lock on," portions of the reinforcingstructure 40 and to form thereby a secure bond between the resinousframework 50a and reinforcing structure 40 in the finished belt 10.

In the preferred embodiment, in which the reinforcing structure 40comprises a woven element, the resinous material 50 must at leastpartially encase the yarns comprising the first surface 41 to form asecure joining therebetween. In the embodiment in which a portion of thevoids 49 extends beyond the external surface 22 of the working member20, the fluid resinous material 50 easily fills the exposed voids 49,thereby encasing the corresponding portions of the reinforcing structure40. It is believed, however, that in the embodiments in which thethickness h of the reinforcing structure 40 is equal to or even lessthan the depth D of the recesses 49, the viscosity of the fluid resinousmaterial 50 could be selected such as to allow the resinous material 50to partially penetrate into the recesses 24, thereby filling the voids49. Because of the woven nature of the reinforcing structure 40, someempty spaces exist between the yarns of the reinforcing structure 40 andthe walls of the recesses 24. Therefore, given a sufficient viscosity ofthe fluid resinous material 50, the fluid resinous material 50 canpenetrate between the yarns of the reinforcing structure 40 and thewalls of the recesses 24, as well as between the individual interwovenyarns of the reinforcing structure 40.

In the embodiments of FIGS. 4B-5, in which portions of the voids 49penetrable by the fluid resinous material 50 extend beyond the externalsurface 22 of the working member 20, a substantial portion of the fluidresinous material 50 is not able to reach beyond the external surface 22of the working surface 20. Therefore, after the resinous material 50 hassolidified, a distance Z is created between the second side 42 ofreinforcing structure 40 and the bottom side 51a of the resinousframework 50a. Of course, relatively small amounts of the fluid resinousmaterial 50 may still, in some embodiments, penetrate between theindividual yarns of the reinforcing structure 40 and between the yarnsof the reinforcing structure 40 and the walls of the recesses 24, andeven reach a "bottom" of the recesses 49. One skilled in the art willunderstand that because of such a penetration of the fluid resinousmaterial 50 into the recesses between the yarns of the reinforcingstructure 40 and/or the walls of the recesses 49, the distance Z maydifferentiate throughout the plane of the belt 10 being constructed,which is acceptable as long as the average distance Z is sufficient toprovide leakage between the belt 10 and the vacuum equipment and toeliminate the sudden application of vacuum pressure to the web disposedon the belt 10, as has been explained above.

The next step in the process of the present invention comprisingsolidifying the fluid resinous material 50. As used herein, the term"solidification" and derivations thereof refer to a process of alteringa fluid to a solid state. Typically, solidification involves a phasechange, from a liquid phase to a solid phase. The term "curing" refersto a solidification in which cross-linking occurs. Preferably, thesolidification of the resinous material 50 comprises curing. A method ofsolidifying the resinous material 50 depends upon its nature. Forexample, photosensitive resins may be cured by UV radiation, asdescribed in commonly assigned U.S. Pat. Nos. 5,334,289; 5,275,700;5,364,504; 5,098,522; 5,674,663; and 5,629,052, all of which areincorporated herein by reference. The thermo-plastic and thermo-settingresins require a certain temperature for solidification. The resinousmaterial 50 comprising multi-component resins or plastics solidifynaturally, during a certain predetermined period of time, by virtue ofbeing mixed together.

In some embodiments the process of solidification of the resinousmaterial 50 may begin as early as right after the fluid resinousmaterial 50 has been deposited onto the molding surface 71, FIG. 5.Preferably, solidification continues while the reinforcing structure 40and the molding surface 71 are in face-to-face relationship. As anexample, FIG. 5 schematically shows a curing device 80 juxtaposed withthe surface opposite to the working surface 21b of the band 20b. Oneskilled in the art will understand that, depending on the nature of theresinous material 50 and the method of its solidifying, the curingdevice 80 may be located in other locations. The examples of the curingdevice 79 include, but are not limited to: a heater for increasingcross-linking reaction rates or condensing rates for condensingpolymers; a cooler for solidifying thermoplastics; various apparatusesproviding an infra-red curing radiation, a microwave curing radiation,or an ultra-violet curing radiation; and the like.

In the exemplary embodiment of FIG. 4, the photosensitive resinousmaterial 50 is cured by exposing it to curing radiation, i. e., thelight of activating wavelength through the mask, thereby inducing curingof the resinous material 50 in those portions that are not shielded bythe non-transparent regions of the mask 15. A curing device 80,including a source of curing radiation 16, may comprise an exposure lampproviding illumination primarily within the wavelength which causescuring of the liquid photosensitive resin 50. Any suitable source ofillumination, such as mercury arc, pulsed xenon, electrodeless andfluorescent lamps, can be used. Commonly assigned patent application,Ser. No. 08/799,852, entitled "Apparatus for Generating ParallelRadiation For Curing Photosensitive Resin" filed in the name of Trokhanon Feb. 13, 1997; and commonly assigned patent application, Ser. No.08/858,334, entitled "Apparatus for Generating Controlled Radiation ForCuring Photosensitive Resin" filed in the names of Trokhan et al. onFeb. 13, 1997, and its continuation Ser. No. 08/958,540 filed on Oct.24, 1997 are incorporated herein by reference for the purpose of showingseveral embodiments of the apparatus for curing radiation 16 which canbe used for solidifying the resinous material 50 comprising aphotosensitive resin.

In the embodiment of FIG. 4, a step may be preferred of removing fromthe reinforcing structure 40 substantially all of the uncured resinousmaterial 50, i. e., that resinous material 50 which was shielded by thenon-transparent regions of the mask 15 from exposure to the curingradiation. A vacuum may be applied from a vacuum apparatus 18a to acomposite of reinforcing structure 40 and partly cured resinous material50 to remove a substantial quantity of the liquid (i. e., uncured)resinous material 50 from the composite. Then, a shower 17 may be usedto wash out remains of the uncured resinous material 50 from thecomposite. Then, the vacuum may once again be applied, from a vacuumapparatus 18b, to remove any residual liquid resinous material 50 andshower liquid. Optionally, there can be a second exposure (not shown) ofthe resinous material 50 to the curing radiation to complete the curingof the resinous material 50 and to increase the hardness and durabilityof the resinous framework 50a of the belt 10 being constructed. Theprocess continues until the entire length of the reinforcing structure40 has been treated and converted into the belt 10.

The thermo-sensitive resinous material 50 may be solidified naturally,at a room temperature. In the embodiment shown in FIG. 5, the step ofsolidifying the fluid resinous material 50a may be provided bymaintaining the resinous material 50 associated with the reinforcingstructure 40 and the patterned molding surface 71 for a pre-determinedperiod of time. During this time, the resinous material 50 solidifiessufficiently to be able to retain its desired shape after it has beendisassociated from the molding surface 70. In the embodiment of FIG. 5,the process of solidification of the resinous material 50 may beginright after the fluid resinous material 50 has been deposited onto themolding surface 71. Solidification continues while the reinforcingstructure 40 and the molding surface 71 are in a face-to-facerelationship, beginning at the nip formed between the support roll 79band the band 20b. From this point on, the corresponding portions of thereinforcing structure 40 recessed within the working surface 21 and themolding surface 71 travel in a face-to-face relationship during apre-determined period of time sufficient to cause the resinous material50 to be transferred from the molding pockets 72 of the molding surface71 onto the reinforcing structure 40 and at least partially solidifysuch as to retain the shape after the molding surface 71 hasdisassociated from the reinforcing structure.

Optionally, solidification accelerators may be used to speed up theprocess of solidification of the resinous material 50. As used herein,"solidification accelerators" refers to materials that, when added tothe resinous material 50, shorten the time necessary to solidify, andpreferably cure, the resinous material 50. Such solidificationaccelerators preferably should not adversely affect the ultimatephysical properties of the resinous framework 50a being constructed. Theexamples of the solidification accelerator include, but are not limitedto: "SO-CURE Cure Accelerator" ("C-1506," "C-1508," "C-1509," and"C-1511"; and "KICK-IT Cure Accelerator" ("PMC-724," "PMC-726,""PMC-121/30," "PMC-121/50," "PMC-744," "PMC-780," all commerciallyavailable from Smooth-On, Inc., 2000 St. John Street, Easton, Pa.,18042.

Optionally, a step of controlling the caliper of the belt 10 may beprovided in the process of the present invention. The caliper may becontrolled by controlling the depth of recesses 24 in the workingsurface 21. Another way of controlling the caliper comprises changingthe thickness of the resinous material 50 after the resinous material 50has sufficiently joined the reinforcing structure 40, and after theresinous framework 50a has been at least partially formed. For example,the thickness of the resinous material 50 can be adjusted by mechanicalmeans known in the art, and therefore not shown herein. For example acouple of mutually-juxtaposed rolls forming a nip therebetween may beused for controlling the caliper of the belt 10. By adjusting a nipclearance between the rolls, one can control the caliper of the belt 10being constructed. Alternatively or additionally, thecaliper-controlling device may comprise a rotating sanding roll, aplaning knife, a laser, or other means known in the art and suitable forthe purpose of controlling the caliper of the belt 10.

What is claimed is:
 1. A process for making a papermaking beltcomprising a reinforcing structure and a resinous framework joinedthereto, the process comprising the steps of:(a) providing a fluidresinous material; (b) providing a reinforcing structure having a firstside, a second side opposite to the first side, and a thickness definedtherebetween; (c) providing a working surface comprising an externalsurface and a pattern of recesses therein, the pattern of recesseshaving a depth and being structured and designed to receive thereinforcing structure therein; (d) at least partially disposing thereinforcing structure in the recesses of the working surface; (e)applying the fluid resinous material to the reinforcing structure; and(f) solidifying the fluid resinous material to form a patterned resinousframework joined to the reinforcing structure.
 2. The process accordingto claim 1, wherein in the step (b) the reinforcing structure has voidsintermediate the first side and the second side, the voids beingpenetrable by the fluid resinous material.
 3. The process according toclaim 2, wherein in step (e) the resinous material occupies at leastsome of the voids in the reinforcing structure.
 4. The process accordingto claim 3, wherein in the step (d) the reinforcing structure isdisposed in the pattern of recesses to extend beyond the externalsurface of the working surface.
 5. The process according to claim 4,wherein a portion of the voids penetrable by the fluid resinous materialextends beyond the external surface of the working surface.
 6. Theprocess according to claim 1, wherein the reinforcing structurecomprises a woven element.
 7. The process according to claim 2, whereinthe fluid resinous material is selected from the group consisting ofepoxies, silicones, urethanes, polystyrenes, polyolefins, polysulfides,nylons, butadienes, photopolymers, and any combination thereof.
 8. Theprocess according to claim 7, wherein the fluid resinous materialcomprises a photosensitive resin.
 9. The process according to claim 7,wherein the fluid resinous material comprises a thermo-sensitive resin.10. The process according to claim 1, wherein in the step (e) the fluidresinous material is applied to the reinforcing structure in apre-selected non-random pattern.
 11. The process according to claim 1,further comprising the steps of:providing a patterned molding surfacejuxtaposed with the reinforcing structure, the molding surface having apattern of molding pockets therein; and depositing the fluid resinousmaterial into the molding pockets of the molding surface.
 12. Theprocess according to claim 1, further comprising the step ofsubstantially changing a viscosity of at least some of the fluidresinous material applied to the reinforcing structure before the stepof solidifying the fluid resinous material.
 13. A process for making apapermaking belt comprising a reinforcing structure and a resinousframework joined thereto, the process comprising the steps of:(a)providing a fluid resinous material; (b) providing a reinforcingstructure comprising at least one plurality of machine-directional yarnsinterwoven with at least one plurality of cross-machine-directionalyarns, the reinforcing structure having a first side, a second sideopposite to the first side, a thickness defined therebetween, and voidsintermediate the first and second sides, the voids being penetrable bythe fluid resinous material; (c) providing a working surface comprisingan external surface and a pattern of recesses therein, the pattern ofrecesses having a depth less than the thickness of the reinforcingstructure, the pattern of recesses being structured and designed toreceive the reinforcing structure therein; (d) disposing the reinforcingstructure in the recesses such that a portion of the voids penetrable bythe fluid resinous material extends beyond the external surface of theworking surface; (e) applying the fluid resinous material to thereinforcing structure to occupy at least some of the voids in thereinforcing structure; and (f) solidifying the fluid resinous materialto form a patterned resinous framework joined to the reinforcingstructure.